A sensor having a microbridge, on which is arranged a heating element of platinum, is described in European Patent Application No. 0 375 399. Sensors of this type are preferably used as mass flow sensors. To ensure adequate adhesion of the platinum layer, out of which the heating element is patterned to the dielectric substrate, metal oxides are used for the adhesion-promoting layer between Pt and Si.sub.3 N.sub.4.